There is no comparison. I have been to Disneyland, WDW and to Canada's Wonderland. Wonderland is simply a park full of rides. That's it. Fun, sure, but it nothing compared to WDW or DL. Walt's places are experiences which go far beyond simple rides. The attention to detail and customer service are what makes them what they are. The entire day I spent at Wonderland this summer I was thinking, boy could they learn a few things from Disney. Huge lines, no fastpasses. Garbage laying around and staff walking right past it (you'd never see that at WDW). While some of the staff at Wonderland were pleasant, there wasn't the same level of service and attitude that castmembers have. It was simply a minimum wage job - no sense of personal ownership or commitment to customer service. Not to slam Wonderland - it is a really fun place and we certainly didn't have any major issues with the staff. There wasn't any interaction with most of them, no-one spoke to the kids about the rides or anything else, smiled much and all that. I felt that Wonderland was way overpriced and the entire day for my family of 4 could have bought me 1 and a bit worth of tickets for 2 weeks at WDW.
Yes, I confess I am a Disney nut, but WdW is far superior. You'll get more thrill rides at Wonderland, but you won't get all the parades, shows, neat things to explore throughout the whole park (mmmm, the smell of the Main St. bakery in Magic Kingdom is one example), and on and on.... It depends on what you like - it it is all about thrill rides, then Wonderland is the place for you. For many of us, it is the million little things at WDW or DL that make the vacation, and we go for much more than the rides.